Diamonds and pencil lead (known as graphite) are chemically identical. Both are made of 100% carbon atoms. Nothing more, nothing less.How can that be when they’re so completely different in physical appearance?

It’s all in the molecular arrangement of the carbon atoms: the number of atoms in the arrangement and the bonds that form between them.

One type of arrangement creates a diamond molecule.
(mouseover the diamond to see)

Another arrangement makes a graphite molecule.
(mouseover the pencil to see)

Notice the distance between the atoms in each of these molecular patterns. The closer the atoms, the tighter the bond.

Notice the layers of grouped atoms in the graphite molecule. These layers can slough off easily, which is what happens when we write with a pencil. Each layer is composed of a hexagonal (6-sided) array of carbon atoms.

If you isolate one of these layers, you have graphene, a 2-dimensional material (one-atom-thick).

This is where chicken wire comes into the picture. Graphite’s layers and graphene’s single layer of carbon atoms are arrayed in a repetitive hexagonal configuration.

Graphene scientists have discovered that this hexagon array is remarkably strong — significantly stronger than the diamond array. Graphene’s unique structure gives it other properties as well, an amazing combination of many impressive properties.

Graphene is so amazing and so impressive, some scientists call it a miracle material. When have you ever heard a scientist call anything miraculous?

Molecule images courtesy of Eastern New Mexico University, where you can read more about diamonds and graphite.

Because it is only 1 atom thick, graphene has no volume, only surface.

The entire structure of graphene is exposed to that which contacts it — light, heat, a gas, a poison. Any molecule that touches graphene evokes a change in the graphene’s electrical properties, thereby acting as a signal of the presence of that molecule.

This makes graphene a versatile and invisibly small sensor device. A single molecule of a toxic gas can be sensed and signaled by graphene.